Knime 3.7 database connector does not connect to DB2

another user had the same problem when using the db2jc.jar driver but once he used the db2jcc4.jar driver it worked. The reason is that with KNIME 3.5.3 we have added a more strict db connection validation which uses a JDBC 4.0 based method from the driver to check connection validity.
Please make sure that you have only registered the db2jcc4.jar and have removed the db2jcc.jar. You can also see in the log file which driver is used. If the error still persists send me you KNIME log via pm.
If you want to you can also try out our new DB framework which is available as preview via the KNIME Labs. The new framework supports several drivers for the same database and also allows you to adapt the connection validation method. For further details see the this post.